Tag Archive for 'assault gun'

This development of the Sturmgeschütz mounts the Stu. K. 40 assault gun, with muzzle brake, on a Pz. Kpfw. III chassis. The gun. is identical to the Kw.K. 40 with the exception that in the Stu. K. 40 the buffer and recuperator systems are mounted on each side of the barrel to accommodate the S. P. mounting, while the Kw.K. 40 mounts the recoil mechanism above the barrel. The road performance of this vehicle will approach that of the Pz. Kpfw. III tank.

The superstructure is a box-like arrangement, closed in on the top and welded to the chassis. A commander’s cupola, loader’s entrance hatch, and an opening for the sight are provided on the roof of the superstructure. There is no hull entrance door. A circular hole approximately 9 inches in diameter, cut in the rear of the superstructure, houses a small electric fan which draws air into the fighting compartment. A circular plate 12 inches in diameter and 30 mm thick is fitted over the hole at a distance of 3 inches from the superstructure by means of 3 bolts. The thickness of superstructure armor is as follows: front vertical plate 50 + 30 mm, gun mantlet 50 mm, sides 30 mm, top 20 mm. Side skirting armor is often mounted on this vehicle.

The gun has a length of 126 inches, without the muzzle brake, a muzzle velocity of 2525 f/s for the 15.0 lb. projectile and an effective range of 2000 yards firing A.P.C. shell. Its approximate radius of elevation is -5 to + 20°; traverse 10° left and right. It utilizes the following types of ammunition—A.P.C., H.E., and hollow charge. The penetration of A.P.C. shell against homogeneous plate is reported as follows: 500 yards, 4.0 inches at 30° obliquity; 4.8 inches normal—1000 yards, 3.6 inches at 30°, 4.3 inches normal—2000 yards, 2.8 inches at 30°, 3.4 inches normal.

The vehicle is a combination of the Pz. Kpfw. III tank chassis and the 10.5 cm l.F.H. 18 (M) with muzzle brake.

The squat superstructure which replaced the turret of the original tank is similar to the Stu. K. 40. Motor, track, and other chassis mechanisms are the same as those in the standard Pz. Kpfw. III tank and its performance should nearly approximate that vehicle.

The howitzer, Stu. H. 42, is identical to the 10.5 cm l.F.H. 18 (M), except that the former is electrically fired and has the following radius of movement: traverse 20°; elevation -6° to +20°. The piece has a length of 115.75 inches excluding the muzzle brake, which is approximately 15 inches in length. The weight of the gun and cradle is 1.7 tons. Firing a long range shell with supercharge, its muzzle velocity is 1,770 f.s. and its maximum range is 13,480 yards. It fires the 32.6 lb. H.E. shell, a long range H.E. shell, a 32.51 lb. smoke shell, a 25.9 lb. hollow charge shell, and an H.E./incendiary shell.

The Germans have recently begun attaching thin skirting armor plate of from 5 mm to 8 mm thickness on various fighting vehicles, including the Sturmgeschütz. The following theories have been advanced for this development: (1) to break up or deflect 20 mm tungsten carbide core ammunition; (2) to defeat hollow charge shells; (3) to defeat the 14.7 mm Russian antitank rifle; (4) to defeat the American Bazooka.

This version of the Sturmgeschütz is similar to its predecessor, the Stu. G. 7.5 cm K., except for its armament. The 7.5 cm Kw.K. short gun which appeared in the original Sturmgeschutz was replaced by the 7.5 cm Stu. G. lg. K., 87 inches long as shown above. The arrangement of the recoil mechanism also differs, the long version having what appears to be the original mounting provided for the Kw.K. 40 and is evidently a forerunner in its design and development. Photographs show the 7.5 cm Stu. G. lg. K. to be equipped at times with a muzzle brake. The front superstructure has been modified to accommodate the improved armament.

This vehicle is made up of the Pz. Kpfw. III tank chassis and an early development of the 7.5 cm Pak 40, and includes the hull and superstructure improvements made at this time on the original Sturmgeschütz. A roof was added, a commander’s cupola, smoke pot projectors and heavier front plate. The piece represents the trend in design from the short barrel 7.5 cm Kw.K. to the Stu. K. 40.

The Sturmgeschütz is an assault weapon. Unlike the two other classes of self-propelled guns, antitank and artillery, which consist merely of guns placed in the hull of a tank with shields erected around the front and sides thereof, the assault gun is built into the hull and is consequently nearer the ground and has a much more solid superstructure built round the gun. The original Sturmgeschütz consisted of the turretless chassis of a Pz. Kpfw. III tank, upon which was mounted the Stu. G. 7.5 cm K., a short-barreled (69.5 inch) piece found in the first models of the Pz. Kpfw. IV. Since the power plant and other mechanical components of the chassis of the Sturmgeschütz are identical to those of the Pz. Kpfw. III tank, and their weights are approximately the same, the performance data of the two are comparable.

The turret of the original tank has been removed and replaced by a squat superstructure, reducing the height of the vehicle from 8 feet, 3 inches as a tank to 6 feet, 5 inches as an assault weapon. The gun compartment is roofed over, but there is no rotating turret. The fighting compartment is armored as follows: front 53 mm, sides 43 mm, top 11 mm.

The gun, which is mounted low in the hull and fires forward, is identical to the 7.5 cm Kpfw. K. short tank gun, originally the main armament of the Pz. Kpfw. IV tank. It is primarily a close support weapon, the ammunition scale comprising only 25% A.P. against 10% smoke and 65% H.E.; its armor-piercing performance is relatively poor. Its muzzle velocity and maximum range firing H.E. shell is 1,378 f.s. and 6,758 yards, respectively. The penetration of A.P.C.B.C. shell against homogeneous armor is reported as follows: 500 yards, 1.81 inches at 30° obliquity, 2.16 inches normal—1000 yards, 1.61 inches at 30°, 1.97 inches normal—1,200 yards, 1.57 inches at 30°, 1.89 inches normal.

This equipment, consisting of the 7.5 cm Stu. K. 40 (L/48) mounted on the Pz. Kpfw. IV chassis, represents a further development in German assault guns. The design follows that of its predecessor, the Stu. G. 40, mounted on the Pz. Kpfw. III chassis, with the exception that in the later equipment the usual keystone mantlet has been replaced by a cast steel mantlet with curved surfaces to offer the maximum projectile deflection. The mantlet, 130 mm thick, houses the buffer and recuperator.

Armor protection has been increased by the addition of slabs of concrete six inches thick attached to the front plate and the roof over the driver’s compartment by means of wire. The rest of the armor is the same as that provided for the Pz. Kpfw. IV.

The division of chassis space follows the usual design for this type of vehicle, with the driver’s compartment in the front, the fighting compartment in the center, and the engine compartment in the rear.

The gun, the Stu. K. 40 (L/48), with muzzle brake, is a lengthened version of the Stu. K. 40 (L/43) and is similar in design and performance to the Kw. K. 40 (L/48).

In the inset above is shown the 7.5 cm Stu. K. 40 (L/48) mounted on the Pz. Kpfw. III chassis which also has the improved type of rounded gun mantlet.